The broad objectives of this proposal are the preparation, exploration, and exploitation of cage-like polycyclic hydrocarbon systems, especially those with adamantane-like or diamondoid structures. Compounds of this class have received little attention until recently, but already there is considerable documentation to support the expectation that the prospects for finding unusual and useful biological and chemical properties are excellent. In general, the following are proposed: 1. The preparation of polycyclic cage molecules by rearrangement and other more conventional methods which will make these substances readily available. 2. The development of practical methods for the substitution of these molecules at specific positions. The synthesis of polyfunctional derivatives will be emphasized. These will have the functional groups held in fixed and known relationships. 3. The study of the properties of these molecules, with emphasis on biochemical and chemical aspects. The polyfunctional cage systems should be of particular interest in this respect, since the conformations of the substituents can be varied on the rigid skeletal framework. Collaboration with biochemists interested in the interaction of polyamines with nucleic acids will continue, and it is hoped to develop further the interest of others in the potential utility of cage systems.